Antifriction bearing



Sept. 25, 1945. s. A. CROSBY 4 'ANTIFRIC'LI'ION BEARING Filed Sept. 13, 1944 fi'm m 23 fl i Patented Sept. 25, 1945 ANTIFRIC'TION'BEARING Stephen J Crosby; Chicago, 111., assignor ,to.

, Sterling Tool Products Company, a corporation of lllinois Application September 13, 1944, Serial No. 553,834

2 Claims.

This invention relates to antifriction bearings, and more particularly to bearings where pressure is transmitted from one movable member to another through flat contacting surfaces.

The primary object of the invention is to provide improved structure for supporting the bearing parts on the relatively movable parts.

Another object of the invention is to provide an improved way of supporting a bearing insert, of a material such as carbon, in a metallic holder, so that it will not become loose when subjected to wide variations in temperature.

Another object of the invention is to provide improved bearings for transmitting pressure through the counterpoise of rubbing or polishing machines of the type shown in my application Serial No. 504,855, filed October 4, 1943. It has been found that the present carbon and metal bearings are much more efficient than the ball bearings previously used and illustrated in said application.

The invention is illustrated in a preferred embodiment in the accompanying drawing in which-- Figure 1 is a fragmentary sectional view of an antifriction bearing embodying the invention; Fig. 2, a plan view of the same taken as indicated at line 2-2 of Fig. 1; Fig. 3, a plan view of one of the metal pads which makes antifrictional contact with a carbon insert; Fig. 4. a fragmentary vertical sectional view taken as indicated at line 4-4 of Fig. 3; and Fig. 5, a bottom plan view of the opposite side of the metal pad shown in Fig. 3.

Rubbing and polishing machines of the type shown in my application Serial No. 504,855, filed October 4, 1943, have an intermediate metal panel or counterpoise 6 which transmits pressure from a lower panel I to an upper panel 8. In the present invention the intermediate panel 6 is a non-ferrous die casting provided with a carbon insert 9.

It has been found that carbon expands about one and one-half millionths of an inch for each increase of one degree F. in temperature, while zinc, which provides most of the volume in some die castings, expands about sixteen millionths of an inch for each increase of one degree in temperature. It is not uncommon for the temperature of a rubbing machine, during heavy continuous operation to increase from room temperature to 350 F. It will be readily understood that if the carbon insert was of round cylindrical structure, the greater expansion of the die casting or metal holder would cause the insert to become loose. I have found that such loosening can be avoided by providing one or more large V-shaped grooves ID in a carbon insert, which dovetail with the metal holder, provided the side walls of the grooves are properly inclined with respect to the axis of the insert. The inclination of said side walls with respect to the longitudinal axis of the insert should make the same angle as a line extending from the longitudinal axial center of the embedded portion of the insert to an outer junction line between the insert and the metal holder. Thus it will be understood that if a single groove is used, the insert would be shaped like an hourglass. However, it is preferred not to have such a thin section at the center of the insert, and as shown in Fig. 1, two annular grooves are provided, whose walls are inclined as described above. In the drawings 'the bottoms of the grooves come to a sharp point, but it will be understood that these may be rounded slightly without substantially affecting the result. As the metal holder 6 heats up, it expands both longitudinally and laterally, and theoretically there will be a slight sliding movement between the metal and carbon insert along the inclined walls of the grooves. However, the shape of the grooves prevents any loosening of the grip of the holder on the insert.

As the panels I and B are usually of soft nonferrous metal, it is preferred to provide a hardened metal steel pad H in the upper panel, which may be secured in any suitable manner, and a similar hardened steel pad I2 in the lower panel I.

In a rubbing machine, it is desirable to have laterally-extending nibs l3, to which a rubbing pad may be attached. As shown in Fig. 4, the body of the nib may be used to anchor the pad l2 in the panel I. The pad I2 is provided with a downwardly extending shank M, which extends into the hollow nib member and is swaged into its socket, as indicated at I5, to hold the parts firmly together. Preferably a small clearance space I6 is provided between the two parts, so that the pad and nib may be drawn firmly into the opposed cone shaped sockets I1 and [8 of the panel 1. In order to hold the nib l3 against rotation with respect to the panel I, a short metal stud I9 is provided, which extends through an opening 20 in the panel I, and has one end projecting into a socket H in the pad l2, and the other end into a socket 22 provided in the nib member l3. It will be understood that the a cast metal holder member having a carbon insert, said insert having a V-shaped peripheral groove dovetailing with said holder member, the

sidewalls of said groove being inclined from the axis of the insert to substantially the same degree as a line projected from the longitudinal axial center of the embedded portion of the insert to an outer junction line between the metal holder and said carbon insert: and a second holder member having a pad of hardened metal fixed therein, said pad having a fiat face in antifrictional contact with one end of said carbon insert.

2. A bearing member for a device of the character set forth, comprising: a cast metal holder provided with a circular carbon insert, said insert having a plurality of annular grooves dovetailing with said holder, the sidewalls of said grooves, when viewed in longitudinal section, being inclined from the axis of the insert at substantially the same angle as a line extending from the longitudinal axial center of the embedded portion of the insert to an outer junction line between the said insert and the holder.

. STEPHEN A. CROSBY. 

